Isoxazole derivatives of sulfanilamide



Aug. 11, 1964 HIDEO KANO ETAL ,1

ISOXAZOLE DERIVATIVES OF SULFANILAMIDE FiledDeq. e, 1962 TIME IN HOURS 0. 0. o. o. o. o g on w v N Hideo Kano, Masaru Oga/a and Haruo Nishimura INVENTORS BY 01mm. Z Z a! $41M ATTORNEYS United States Patent ISOXAZGLE DERIVATIVES OF SULFANILAMIDE Hideo Kano, Kamikyo-ku, Kyoto-shi, Masaru Ogata,

Kobe-slit, and Haruo Nishimura, Ashiya-shr, Japan, as-

signors to Shionogi & Co., Ltd., Osaka, Japan Filed Dec. 6, 1962, Ser. No. 242,862 Claims priority, application Japan Aug. 21, 1962 2 Claims. (Cl. 260-2399) The present invention relates to halogenated isoxazole derivatives of sufanilarnide. More particularly, it relates to 3-sulfanilarnido-4-halogeno 5 alkylisoxazoles and intermediates therefor.

The said halogenated isoxazole derivatives of sulfanilamide are representable by the formula:

wherein R is lower alkyl (e.g. methyl, ethyl, propyl, butyl) and X is halogen (e.g. chlorine, bromine, iodine).

These halogenated isoxazole derivatives of sulfanilamide of Formula I show high antibacterial activity with low toxicity, characteristically, in vivo. They also show high and prolonged sulfonamide level in blood in vivo.

Accordingly, a basic object of the present invention is to embody 3-sulfanilamido-4-halogeno-S-alkylisoxazoles and intermediates therefor. Another object of the invention is to embody sulfonamides exhibiting high antibacterial activity with low toxicity, particularly in vivo. Another object of the invention is to embody long-acting sulfonamides. A further object of the invention is to embody sulfonamides applicable to living bodies such as animals and human beings for producing high and prolonged sulfonamide level in the blood. These and other objects will be apparent to those skilled in the art to which the present invention pertains from the subsequent description.

The 3-sulfanilamido-4-halogeno 5 alkylisoxazole of Formula I can be prepared by the interaction of 3-amino- 4-halogeno-S-alkylisoxazole representable by the formula:

wherein R and X each has the same significance as designated above, with a p-substituted benzenesulfonrc acid derivative representable by the formula:

(III) "ice XIIHE -NHB wherein R and X each has the same significance as designated above, X is chlorine or bromine and X" is halogen (e.g. chlorine, bromine, iodine). Thus, 3-amino-5- alkylisoxazole may be reacted with chlorine or bromine, preferably in an inert organic solvent (e.g. methanol, ethanol, acetic acid, chloroform, carbon tetrachloride, trichloroethane), while cooling with water or ice, to give 3-amino-4-c'nloroor -bromo-5-alkylisoxazole. Alternatively, 3-amino-5-alkylisoxazole may be reacted with mercuric halide (e.g. mercuric chloride, mercuric bromide, mercuric iodide) in a hydrous medium (e.g. Water, waterrnethanol, water-ethanol, water-acetic acid), preferably while refluxing, followed by the treatment of the resulting 3-amino-4-halogenomercuri-5-alkylisoxazole with a mixture of halogen (e.g. chlorine, bromine, iodine) and its alkali metal salt (e.g. potassium chloride, potassium'bromide, potassium iodide) in a hydrous medium (e.g. water, water-methanol, water-ethanol, water-acetic acid) at room temperature (e.g. about 20 to about 30 C.) or while heating, to give 3-amino-4 halogeno 5 alkylisoxazole. These fundamental procedures may be also carried out with appropriate previous and/ or subsequent treatments which are per se not part of the present invention. In the former procedure for instance, 3-arnino-5-alkylisoxazole may be previously acylated and then subjected to halogenation, followed by deacylation of the acylamino group at the 3-position of the resulting intermediate whereby 3-amino-4-halogeno-S-allrylisoxazole is produced. As specific examples of 3-amino-4-halogeno- 5 alkylisoxazole, there may be included 3-amino-4-chloro-5-methylisoxazole, 3-amino-4-bromo 5-methylisoxazole, 3-amino- 4-iodo-5-methylisoxazole, 3-amino-4-chloro-5-ethylisoxazole, 3-amin0-4-iod0-5-ethylisoxazole, 3-arnin0-4-chloro- S-n-propylisoxazole, 3-amino-4-bromo-5 n-propyl-isoxazole, 3-amino-4-iodo-5 iso-propylisoxazole, 3 amino-4- chloro5-n-butylisoxazole and the like.

The other starting material of the present invention, namely the p-substituted benzenesulfonic acid derivative of Formula III, is usually employed in the preparation of sulfonamides. There maybe generically exemplified pacylaminobenzenesulfonic acid, p-nitrobenzenesulfonic acid, azobenzene-p,p-disulfonic acid, p-acylaminobenzenesulfonic ester, p-nitrobenzenesulfonic ester, azobenzene-p,p'-disulfonic ester, p-acylaminobenzenesulfonyl halide, p-nitrobenzenesulfonyl halide, azobenzene-p,p-disulfonyl halide and the like. The acyl group may not only be alkanoyl (e.g. acetyl, propionyl, butyryl), aryloyl (e.g. benzoyl, toluoyl, xyloyl) and aralkanyol (e.g. phenylacetyl, phenylpropionyl) but also alkoxycarbonyl (e.g. ethoxycarbonyl, propoxycarbonyl), .aryloxycarbonyl (e.g. phenoxycarbonyl, tolyloxycarbonyl) and aralkoxycarbonyl (e.g. benzyloxycarbonyl, phenethyloxycarbonyl), although the latter three are sometimes not included in the category of acyl. Further, the ester may be an alkyl ester (e.g. methyl ester, ethyl ester, propyl ester), aryl ester (e.g. phenyl ester) and aralkyl ester (e.g. benzyl ester, phenethyl ester), inclusively.

The following p-substituted benzenesulfonic acid derivatives may be given by way of specific exemplification: p-acetylaminobenzenesulfonic acid, .p-propionylaminobenzenesulfonic acid, p-benzoylarninobenZene-sulfonic acid, p-ethoxycarbonylaminobenzenesulfonic acid, p-benzyloxycarbonylaminobenzenesulfonic acid, p-nitrobenzenesulfonic acid, methyl p-acetylaminobenzenesulfonate, ethyl zinc, tin) with an acid glacial acetic acid containing p-actylaminobenzenesulfonate, benzyl p-actylaminobenzenesulfonate, ethyl p-nitrobenzenesulfonate, ethyl azobenzene-p,p-disulfonate, phenyl azobenzene-p,p'-disulfonate, o-acetylaminobenzenesulfonyl chloride, p-acetylaminobenzenesulfonyl bromide, p-propionylaminobenzenesulfonyl chloride, p-benzoylarninobenzenesulfonyl chloride, p-ethoxycarbonylaminobenzenesulfonyl chloride, p-phenoxycarbonylaminobenzenesulfonyl bromide, o-benzyloxycarbonylaminobenzenesulfonyl chloride, pnitrobenzenesulfonyl chloride, azobenzene-p,p-disulfonyl chloride, azobenzene-p,p'-disulfonyl bromide, etc. Of these p-substituted benzenesulfonic acid derivatives, palkanoylaminobenzenesulfonyl halide may be used with greatest advantage in view of its excellent reactivity.

According to the process of the present invention, the said two starting materials are firstly subjected to condensation. The reaction can be executed by treating a 3-amino-4-halogeno-5-alkylisoxazole of Formula II with a p-substituted benzenesulfonic acid derivative of Formula III in an inert solvent. The inert solvent is required to be able to dissolve at least one of the starting materials and may be generally selected from lower alkanols (e.g. methanol, ethanol), lower aliphatic ketones (e.g. acetone, methyl ethyl ketone), aromatic hydrocarbons (e.g. benzene, toluene), aliphatic esters (e.g. methyl acetate, ethyl acetate), ethers (e.g. diethyl ether), cyclic ethers (e.g. dioxane, tetrahydrofuran), halogenalkanes (e.g. chloroform, dichloroethane, carbon tetrachloride) and the like. When a p-substituted benzenesulfonyl halide is used as the starting material, the condensation is a kind of deacidation reaction, and the presence of a basic substance is preferred. As the basic substance, there may be employed organic bases such as pyridine bases (e.g. pyridine, picoline, lutidine, collidine) and trialkylamines (e.g. triethylarnine) or inorganic bases such as alkali metal carbonates (e.g. sodium carbonate, potassium carbonate) and alkaline earth metal carbonates (e.g. calcium carbonate, barium carbonate). These basic substances may be used in the form of mixture, suspension or solution in the said inert organic solvent or, in the case of liquid, alone. The reaction temperature may be correlated to the starting materials and/or the reaction medium.

As the result of the condensation, there is obtained 3- (p-substituted benzenesulfonylamino -4-h alogeno-S-alkylisoxazole representable by the formula:

XTENHS o 2G2 wherein R, X and Z each has the same significance as designated above.

The thus-prepared 3-(p-substituted benzenesulfonylamino) -4-halogeno-5-alkylisoxazole of Formula IV is next subjected to the conversion of the p-substituent on the benzene ring into an amino group. The conversion procedure to be applied may be correlated to the said psubstituent. When the p-substituent is an acylamino group, the conversion can be effected by hydrolysis. The hydrolysis reaction may be carried out in per se conventional manner, i.e. heating with acid or alkali. When the p-substituent is a nitro group, there is adopted a reduction procedure which is usually employed for the conversion of the nitro group on an aromatic ring into an amino group. For instance, there may be employed the reduction using a reducing agent such as metal-acid, metalalkanol and metal-liquid ammonia, catalytic reduction and electrolytic reduction. The method wherein the reduction is carried out using a combination of a metal (e.g. (e.g. hydrochloric acid, acetic acid, hydrogen chloride) at room temperature or while heating is particularly preferred from the economical viewpoint. The catalytic reduction using nickel catalyst, palladium catalyst or platinum catalyst is also preferred from the standpoint of easy oper- 4. ation and rare side-reaction. When the p-substituent is an azo group, the 3-(p-substitutcd benzenesulfonylamino)- 4-halogeno-5-alkylisoxazole of Formula IV can be writwherein R and X each has the same significance as designated above. In this case, the conversion may be accomplished by reduction. For instance, there may be employed the reduction using a reducing agent such as stannous chloride-hydrochloric acid and alkali metal dithionite, catalytic reduction and electrolytic reduction. The catalytic reduction using Raney nickel in an aqueous solution of alkali hydroxide or platinum oxide in dioxane is particularly preferred.

The product of the present invention is 3-sulfanilarnido- 4-halogeno-S-alkylisoxazole of Formula I, which includes specifically the following compounds: 3-sulfanilamido-4- chloro-S-methylisoxazole, 3-sulfanilamido 4 bromo 5- methylisoxazole, 3-sulfanilaniido-4 iodo 5 methylisoxazole, 3-snlfanilamido-4-chloro-5-ethylisoxazole, 3-sulfanilamido 4 bromo-S-ethylisoxazole, 3 sulfanilamitlo-4 iodo-S-ethylisoxazole, 3-sulfanilamido-4-chloro-5-n propylisoxazole, 3-sulfanilamido-4-bron1o-5-iso propylisoxazole, 3-sulfanilamido-4-icdo-5-n-propylisoxazole, 3-sulfanilamido-4-bromo-S-n-butylisoxazole, 3-sulfanilamido 4- iodo-S-n-butylisoxazole, etc.

These 3-sulfanilamido-4-halogeno-5-alkylisoxazoles of Formula I are useful as antibacterial agents in combating infections of pathogenic bacteria. Especially, 3-sulfanilamido-4-iodo-5-methylisoxazole is the presently-preferred one; its animal and clinical test data are set forth in the following tables, compared with the sulfonamide, 3-sulfanilamido-S-methylisoxazole [U.S. Patent No. 2,888,- 455].

The in vitro antibacterial spectra of the sulfonamides were determined by an agar streak dilution method. Serial two-fold dilutions of the sulfonamide were prepared in synthetic medium and the surface of the agar was streaked with suitable dilution of young broth cultures. The lowest concentration of sulfonamide which prevented visible growth after 24 hours of incubation at 37 C. was designated as the minimal inhibitory concentration. The results are shown in Table I.

TABLE L-ANTIBACTERIAL SPECTRA (IN VITRO) From this table, it is seen tha in vitro antibacterial spectrum of 3-sulfanilarnido-4-iodo-S-methylisoxazole is quite identical with that of 3-sulfanilamido-S-methylisoxazole, although there is a slight diiference in activity.

To determine the in vivo activity of the sulfonamides, infections with Diplococcus pneumoniae and Klcbisiella pneumoniae were produced in mice, in groups of 10 mice, by intraperitoneal injections of the bacteria using MLD (minimum lethal dose) of the bacterial cultures. The mice were treated 3, 24, 48, 72 and 96 hours after infection. The sulfonamide, emulsified with gum arabic, was administered orally to the groups of mice, and survival of infected mice was recorded up to 10 days after infection, at which time the tests were terminated. The percentage deaths were plotted against logarithmic dose on logarithmic probability scale paper and the dose of sulfonamide (mg/kg.) giving protection to 50% of the mice was read off from the graph. The results are shown in Table II.

TABLE II.ANTIBACTERIAL ACTIVITY (IN VIVO) (a) Diplococcus pneumoniae, Type 1 No. Median Dosage Alive/ Percent Efiective sulfonamides (mgJkg/ No. Effect Dose day) Tested (EDw) s-I e.)

3-Sulfanilarnido-4-iodo-5- 500 3/10 30 methylisoxa zole 750 4/ 10 40 780 1,000 7/10 70 3-Sultanilamido-fi-methyl- 500 1/10 10 isoxazole 750 3/10 30 920 (b) Klebsiella pneumonlae N0. Median Dosage Alive] Percent Efiective sulfonamides (mg/kg] No. Efieet Dose day) Tested (EDao) 3-Sulfanilamid0-4-iod0-5- 250 1/10 10 methyliso xa zole 500 5 10 50 540 750 9/10 90 1,000 10/10 100 3-Sulfanilamido-5-methyl- 250 /10 0 isoxazole 500 3/10 30 650 From the above table, it can be pointed out that 3-sulfanilamido-4-iodo-S-methylisoxazole is more effective than 3-sulfanilamido-5-rnethylisoxazole against pneumococcal and Klebsiella infections.

In order to ascertain the absorption of the sulfonamides in human beings, the sulfonamides were orally administered to human subjects at a dose of 2 grams, and citrated venous samples of blood were obtained before and at various intervals after administration. The blood specimens were centrifuged within 30 minutes of drawing, and plasma harvested into sterile test tubes. The thus-obtained plasma samples were analyzed for free sulfonamide by the Tsuda method [Yakugaku (Science of Drugs), vol. 2, 12 (1948)]. The averages of free values of both sulfonamides obtained at the various intervals are shown graphically in the accompanying figure of drawings. The solid line represents average free-3-sulfanilamido-4-iodo- S-methylisoxazole plasma level and the broken line shows average free 3-sulfanilamido-S-methylisoxazole plasma level.

From the said figure, it can be seen that 3-sulfanilamido 4 iodo methylisoxazole and 3 sulfanilamido-S-methylisoxazole are rapidly absorbed and reach identical maximum plasma peaks, 4 hours after administration, but the former shows a higher maximum peak value with a slower drop in concentration than the latter. It is, therefore, clear that 3-sulfanilamido-4-iodo-S-methylisoxazole shows far better maintenance of plasma levels than does 3-sulfanilamido-S-methylisoxazole.

To determine the acute toxicity, the sulfonamides were emulsified with gum arabic and administered orally to mice. The animals were observed for 7 days and deaths were recorded each day. The median lethal dose (LD was determined graphically by plotting the dilution factor of the dose against the percentage deaths, using logarithmic probability scale paper. The results are shown in Table III.

TABLE III.-ACUTE TOXICITY (PER OS, IN MICE) Median Lethal sulfonamides Dose (LDro) s-I e.)

3-5ulfanilarnido-4-iodo-5-methylisoxazole 4, 500 3-Sulfanilamido-5-rnethylisoaxzole 2, 500

amido-4-halogeno-5-alkylisoxazoles of Formula I also have similar activities.

The 3-sulfanilamido-4-halogeno-5-alkylisoxazoles of the present invention can be prepared and administered to living bodies such as animals and human beings in a wide variety of oral and parenteral dosage forms, singly or in a mixture with other coacting compounds. They can be associated with a carrier which can be a solid material or liquid, in which the sulfonamides are dissolved, dispersed or suspended. The solid composition can take the form of tablets, powders, capsules or the like preferably in unit dosage forms for simple administration or precise dosages. Prior to the preparation, conventional changes may be made on the sulfonamides. In a per se conventional manner, for instance, the sulfonamides may be converted into the alkali metal-cg. sodiumsalts thereof, which are suitable for liquid form preparations, such as those for injection. However, the administration of these derivatives to living bodies for the production of high and prolonged sulfonamide level in blood is intended to be within the scope of the present invention, because it is substantially equal to the administration of the sulfonamides per se.

The following examples represent presently-preferred embodiments of the present invention, but it is to be understood that the examples are given by way of illustration only and not of limitation. The relationship of parts by weight to parts by volume is the same as that between grams and milliliters. Temperatures are set forth in degrees centigrade.

EXAMPLE 1.-3-AMINO-4-CHLORO-5METHYLISOXAZOLE Into a solution of 3-amino-S-methylisoxazole (1 part by weight) in glacial acetic acid (5 parts by vo1urne), chlo rine gas is bubbled while cooling with water. After 30 minutes, an aqueous solution of sodium bisulfite is added to the reaction mixture, which is then shaken with chloroform. The chloroform layer is washed with water to remove acetic acid, and dried. After removal of the solvent, the residue is crystallized from cyclohexane to give 3-amino-4-chloro-5-methylisoxazole (0.7 .part by weight) as silky threadlike colorless needles melting at 89 to 91 C.

Analysis.-Calcd. for C H ON Cl: C, 36.10; H, 3.77; N, 21.05. Found: C, 36.55; H, 4.30; N, 20.76.

EXAMPLE 2.3-AMINO4-BROMO-5JIETHYLISOXAZOLE which is then shaken with chloroform. The chloroform layer is washed with water and dried. After removal of the solvent, the residue is crystallized from cyclohexane t0 give 3-amino-4-bromo-5-methylisoxazole (0.7 part by weight) as colorless needles melting at 77 to 78 C.

Analysis-Calm. for C H ON Br: C, 27.12; H, 2.82; N, 15.82. Found: C, 27.55; H, 2.86; N, 15.74.

EXAMPLE 3.-3-AMINO-4-CHLORO-5-METHYL- 'ISOXAZOLE 3-acetylamino-S-methylisoxazole prepared from 3-amino-5-methylisoxazole (1 part by weight) by a conventional EXAMPLE 4.3-AMINO-4-IODO-5METHYLISOXAZOLE A solution of 3-amino-5-methylisoxazole (1.5 parts by weight) in a small amount of water and a solution of mercuric chloride (9 parts by weight) in hot water (200 parts by volume) are combined together. The resultant mixture is refluxed for about 1 hour and then cooled. The precipitate is collected by filtration whereby 3-amino- 4-chloromercuri-5-methylisoxazole (4.5 parts by Weight) is obtained as white crystals melting at 223 C. (decomp). The 3-amino-4-chloromercuri-S-methylisoxazole (3.5 parts by weight) is mixed with a solution of iodine (2.7 parts by weight) and potassium iodide (8 parts by weight) in Water (50 parts by volume) and stirred for 30 minutes. To the reaction mixture, there is added sodium bisulfite to decolorize the color caused by excess of iodine. The resulting mixture is shaken with chloroform and the chloroform layer is dried. After removal of the solvent, the residue is crystallized from water to give 3-amino-4- iodo-S-methylisoxazole (0.8 part by weight) as colorless prisms melting at 104 to 104.5 C.

Analysis.-Calcd. for C H ON I: C, 21.44; H, 2.25; N, 12.50. Found: C, 21.67; H, 2.17; N, 12.73.

EXAMPLE 5.3-AMINO-4-BROMO-5-METHYLIS OXAZOLE A solution of 3-amino-5-methylisoxazole 1.5 parts by weight) in a small amount of water and a solution of mercuric chloride (9 parts by weight) in hot water (200 parts by volume) are combined together. The resulting mixture is refluxed for about 1 hour and then cooled. The precipitate is collected by filtration whereby 3-amino- -chloromercuri-5-methylisoxazole (4.5 parts by weight) is obtained. The 3-amino-4-chloromercuri-S-methylisoxazole (3.5 parts by weight) is mixed with a solution of bromine (1.7 parts by weight) and potassium bromide (5.8 parts by weight) in water (50 parts by volume) and stirred for 30 minutes. To the reaction mixture, there is added sodium bisulfite to decolorize the color caused by excess of bromine. The resulting mixture is shaken with chloroform and the chloroform layer is dried. After removal of the solvent, the residue is crystallized from hexane to give 3-amino-4-bromo-S-methylisoxazole (0.8 part by weight).

EXAMPLE 6.3-SULFANILAMIDO-4-CHLORO-5- METHYLISOXAZOLE To a solution of 3-amino-4-chloro-5-methylisoxazole (6 parts by weight) in a mixture of pyridine (4 parts by volume) and benzene (20 parts by volume), there is added p-acetylaminobenzenesulfonyl chloride (11 parts by weight), and the resultant mixture is stirred for 2 hours at 50 C. After cooling, the benzene layer is removed by decantation. To the residue, there is added water and stirring efiected to gradually precipitate crystals. The

crystals are collected by filtration and heated with aqueous 10% sodium hydroxide solution (40 parts by volume) on a water bath for 1 hour. After cooling, the reaction mixture is acidified with hydrochloric acid. The precipitated crystals are collected by filtration and recrystallized from ethanol to give 3-sulfanilamido-4-chloro-5-methylisoxazole (4.4 parts by volume) as colorless prisms melting at 182 to 184 C. By repetition of the recrystallization, there are obtained pure crystals melting at 187 to 188 C.

Analysis-Calm. for C H O N SCl: C, 41.81; H, 3.49; N, 14.63. Found: C, 42.02; H, 3.57; N, 14.60.

EXAMPLE 7.3'SULFANILAMIDOA-BROMO-S- METHYLISOXAZOLE To a solution of 3-amino-4-brorno-5-methylisoxazole (20 parts by weight) in a mixture of pyridine (15 parts by volume) and benzene (100 parts by volume), there is aided p-acetylaminobenzenesulfonyl chloride (25 parts by Weight), and the resultant mixture is stirred for 2 hours at 50 C. The precipitated crystals are collected by filtration and hydrolyzed with 10 aqueous sodium hydroxide solution (100 parts by volume) While heating on a water bath. The precipitated crystals are collected by filtration and recrystallized from ethanol to give 3-sulfanilamido- 4-bromo-5-methy1isoxazole (9.5 parts by weight) as colorless needles melting at 183 to 184 C.

Analysis-Calm. for C H O N SBr: C, 36.11; H, 3.00; N, 12.34. Found: C, 36.37; H, 2.92; N, 12.38.

EXAMPLE S.3-SULFANILAMIDO-4-IODO-5- METHYLIS OXAZOLE To a solution of 3-amino-4-iodo-5-methylisoxazole (2.2

parts by weight) in a mixture of pyridine (1.5 parts by volume) and benzene 20 parts by volume), there is added p-acetylaminobenzenesulfonyl chloride (2.5 parts by weight), and the resultant mixture is stirred for 2 hours at 50 C. The precipitated crystals are collected by filtration and hydrolyzed with 10% aqueous sodium hydroxide solution (10 parts by volume) while heating on a water bath. The precipitated crystals are collected by filtration and recrystallized from ethanol to give 3-sulfanilamido-4- iodo-S-methylisoxazole (1 part by weight) as colorless needles melting at 201 to 202 C. (decomp.). By repetition of the recrystallization, there are obtained pure crystals melting at 209 to 210 C. (decomp.).

Analysis.Calcd. for C H O N SI: C, 31.66; H, 2.64; N, 11.11. Found: C, 32.16; H, 2.72; N, 10.71.

While the foregoing examples are directed to simplest and presently-preferred specific embodiments, more complex embodiments wherein the moiety corresponding to R is a lower alkyl higher than methyl may mutatis mutandis be similarly prepared and used.

What is claimed is:

1. 3-sulfanilamido-4-iodo-5-lower alkylisoxazole.

2. 3-sulfanilamido-4-iodo-5-methylisoxazole.

References Cited in the file of this patent UNITED STATES PATENTS 2,494,524 Sprauge Jan. 10, 1950 2,525,321 Hultquist et a1 Oct. 10, 1950 2,883,391 Swain Apr. 21, 1959 2,888,455 Kano et al May 26, 1959 2,988,547 Achelis et a1 June 13, 1961 3,048,519 Fedrick et a1 Aug. 7, 1962 3,072,527 Cohen et al. Jan. 8, 1963 3,073,839 Kano et al. Jan. 15, 1963 3,073,851 Steiger Jan. 15, 1963 

1. 3-SULFANILAMIDO-4-IODO-5-LOWER ALKYLISOXAZOLE. 